
# 写个程序，打印1~20 的整数，打印在4行内
# 1 2 3 4 5
# 6 7 8 9 10
# 11 12 13 14 15
# 16 17 18 19 20
i = 1
while i <= 20:
    print('%2d' % i, end=' ')
    # if i == 5 or i == 10 or i == 15 or i == 20:
    if i % 5 == 0:
        print()
    i += 1
print()

